I can't do stuff like this on GameKnot. The ruthless efficiency of their computers will not let me, so I'm going to post my puzzle here, and a stripped down version there.
This arose from a game I'm playing right now where the player is in
zugzwang, an arrangement where every choice of moves is bad. In this case, not only are the moves bad, they're fatal: every move leads to checkmate.
While I was working on the problem of how to efficiently checkmate my opponent, I came across this pleasing line which passes up a possible mate in three moves. The object of this puzzle is to checkmate white's king in
11 moves, while forcing him across the board. Take white's king on a tour.
Black to move and mate in 11.
Don't cheat!
1. ... Qe3+
2. Kc2 d3+
3. Bxd3 Qd2+
4. Kb3 Qxd3+
5. Bc3 Nd2+
6. Ka4 Bd7+
7. Ka5 Bb4+
8. Kxb4 a5+
9. Kc5 b6+
10. Kxb6 Qd6+
11. Kb7 Qb8#
or
1. ... Qe3+
2. Kc2 d3+
3. Bxd3 Qd2+
4. Kb3 Qxd3+
5. Bc3 Nd2+
6. Ka4 Bd7+
7. Ka5 Bb4+
8. Bxb4 Nxc4+
9. Nxc4 b6+
10. Ka6 Qxc4+
11. Kb7 Qc8#
P.S. The two mates in three moves are:
1. ... Qe3+
2. Kc2 Qd2+
3. Kb1 Qd1#
and
1. ... Qe3+
2. Kc2 Qd2+
3. Kb3 Nc5#